Baltimore police denied a media report on Monday they had shot a black man while trying to take him into custody, saying the man`s firearm went off accidentally while officers were arresting him and that no one was injured.

Officials in Ferguson, Missouri, have released the full content of racially charged and religiously insensitive emails, including about President Barack Obama, sent between the city’s former court clerk and two ex-police supervisors.

Police arrested at least two people today as nightly protests in the racially troubled US suburb of Ferguson over the police killing of unarmed black teenager Michael Brown shifted into the heart of St Louis.

Nearly 48 hours after two officers were shot in Ferguson, Missouri, investigators had dozens of leads but no arrests to report on Friday in the hunt for a gunman who turned a late-night protest against police into bedlam.

Investigators are following dozens of leads in the hunt for whoever shot and wounded two police officers in Ferguson, Missouri, during a protest rally this week, the head of the St. Louis County police said on Friday.

Two Secret Service agents being probed for allegedly crashing a car into White House security barriers after a boozy night out drove right through a bomb investigation scene there, The Washington Post reported Friday.

The shooting of two police officers at a protest in Ferguson, Missouri, triggered a sweeping manhunt for suspects on Thursday and ratcheted up tensions in a city at the centre of a national debate over race and policing.

The police chief in Ferguson, Missouri resigned Wednesday after a scathing US Justice Department report into the shooting of unarmed black teenager Michael Brown by one of his officers, US media reported.

The city manager of Ferguson, Missouri, has resigned in the wake of a US Justice Department probe that found a range of systemic racially biased practices by the police and municipal court, the city said on Tuesday.

US President Barack Obama has condemned the police in the Missouri city of Ferguson for "oppressive and abusive" actions against African-Americans and called for criminal justice reform as part of the modern struggle for civil rights.